METHOD OF MANUFACTURING ACCURACY EVALUATION OF WIND TUNNEL MODELS BY MEASURING DATA FROM A COORDINATE-MEASURING MACHINE

摘要

The main geometric features of wind tunnel models and their units, such as the accuracy of the model's location in the wind tunnel's test section, accuracy of the model's assembly, deviations from specified aerodynamic twists and V-shaped wings, reproduction of the outlines of the main surface profiles, etc., are evaluated by the model's surface points by measuring the data using a coordinate-measuring machine (CMM). Unlike traditional evaluations commonly found in engineering, in which the accuracy of a part is found through measuring point deviations from the part's surface, the separation of errors by components in the model's geometric features required to form the special processing procedure based on a search of the geometric correspondence between the measuring points and points of mathematical model and matching them by using a least-squares method. A way to increase the convergence of the measuring data matching procedure to the mathematical model is proposed for weakly curved surfaces. An example of evaluating manufacturing accuracy of a large-size wind tunnel half-model of an airliner is presented.